本文為英文版的機器翻譯版本，如內容有任何歧義或不一致之處，概以英文版為準。

# 從 取得指標 CloudWatch
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## 列出指標
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若要列出 CloudWatch 指標，請建立 [ListMetricsRequest](https://sdk.amazonaws.com/java/api/latest/software/amazon/awssdk/services/cloudwatch/model/ListMetricsRequest.html) 並呼叫 CloudWatchClient 的 `listMetrics`方法。您可以使用 `ListMetricsRequest` 來根據命名空間、指標名稱或維度，篩選傳回的指標。

**注意**  
您可以在 Amazon CloudWatch 《 使用者指南》的指標和維度參考中找到 AWS 服務發佈的指標和維度清單。 [Amazon CloudWatch](https://docs.aws.amazon.com//AmazonCloudWatch/latest/monitoring/aws-services-cloudwatch-metrics.html)

 **匯入** 

```
import software.amazon.awssdk.regions.Region;
import software.amazon.awssdk.services.cloudwatch.CloudWatchClient;
import software.amazon.awssdk.services.cloudwatch.model.CloudWatchException;
import software.amazon.awssdk.services.cloudwatch.model.ListMetricsRequest;
import software.amazon.awssdk.services.cloudwatch.model.ListMetricsResponse;
import software.amazon.awssdk.services.cloudwatch.model.Metric;
```

 **Code** 

```
    public static void listMets( CloudWatchClient cw, String namespace) {

        boolean done = false;
        String nextToken = null;

        try {
            while(!done) {

                ListMetricsResponse response;

                if (nextToken == null) {
                   ListMetricsRequest request = ListMetricsRequest.builder()
                        .namespace(namespace)
                        .build();

                 response = cw.listMetrics(request);
                } else {
                  ListMetricsRequest request = ListMetricsRequest.builder()
                        .namespace(namespace)
                        .nextToken(nextToken)
                        .build();

                response = cw.listMetrics(request);
            }

            for (Metric metric : response.metrics()) {
                System.out.printf(
                        "Retrieved metric %s", metric.metricName());
                System.out.println();
            }

            if(response.nextToken() == null) {
                done = true;
            } else {
                nextToken = response.nextToken();
            }
        }

        } catch (CloudWatchException e) {
            System.err.println(e.awsErrorDetails().errorMessage());
            System.exit(1);
        }
    }
```

透過呼叫其 [ 方法，指標會在 ](https://sdk.amazonaws.com/java/api/latest/software/amazon/awssdk/services/cloudwatch/model/ListMetricsResponse.html)ListMetricsResponse`getMetrics` 中傳回。

結果可能會*分頁*。若要擷取下一批次結果，請在回應物件上呼叫 `nextToken`，並使用字符值來建置新的請求物件。然後以新的請求再次呼叫 `listMetrics` 方法。

請參閱 GitHub 上的[完整範例](https://github.com/awsdocs/aws-doc-sdk-examples/blob/f4eaf2b2971805cfb2b87a8e5ab408f83169432e/javav2/example_code/cloudwatch/src/main/java/com/example/cloudwatch/ListMetrics.java)。

## 其他資訊
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+  Amazon CloudWatch API 參考中的 [ListMetrics](https://docs.aws.amazon.com//AmazonCloudWatch/latest/APIReference/API_ListMetrics.html)